Full-Bridge Single-Inductor-Based Buck-Boost Inverters

The output voltage of renewable energy sources is influenced by environmental conditions. To compensate for the variations of voltage, a buck-boost power conditioning system can be used. This article presents a full-bridge single-inductor-based buck-boost inverter. Its output voltage can be greater or lower than the input voltage depending on the controllable duty ratio. This inverter features bidirectional and reactive power flow operations with no high-frequency common-mode voltage. The unique feature of the proposed inverter is using a single inductor in the power train, which enhances the power density. Moreover, only two switches can operate at high frequency. This enables the inverter to be made with the high efficiency and simple circuit configuration. Based on the proposed full-bridge inverter, a novel cascaded buck-boost inverter is also presented. It retains all the benefits of the proposed full-bridge inverter. The theoretical analysis of the proposed full-bridge inverter is first explained in detail. It is then extended to a cascaded inverter. Thereafter, the practical effectiveness of the proposed inverters is verified with the experimental tests by implementing the hardware prototypes of 110 V-rms, 60 Hz, and 500 W for full-bridge single-inductor-based buck-boost inverter, and 220 V-rms, 60 Hz, and 1000 W for the cascaded inverter.